Description: (Taken directly from the application) The overarching mission of the MB/MG Core is to discover the molecular bases underlying obesity and its comorbidities. To achieve this mission, the Core performs studies in humans and rodents to identify mutations in candidate genes as well as rodent studies to define the functions of candidate genes by genetic manipulations using transgenic methodologies. Through collaborative efforts with other Cores of the NYORC, the effects of defined genetic alterations in humans and rodents are thoroughly characterized for their effects on ingestive behavior, energy balance, body composition, and endocrine function. The role of candidate molecules in relevant tissues, such as neurons, adipocytes and pancreatic islets, which are related to energy homeostasis can be sharply delineated by thorough and definitive experimentation on both human subjects and rodent models. Due to the establishment of dose ties among the various Cores of the NYORC, opportunities to explore new genetic models of obesity are greeted with enthusiasm by the collaborators of the MB/MG Core. The addition of the Columbia University Microarray Facility (under the direction of Dr. Anthony Ferrante) to the Columbia Genome Center and the Division of Molecular Genetics (Drs. Leibel and Chua are members of the Division) allows the massively parallel analysis of gene expression in models of obesity. The broad expertise of the MB/MG staff allows the MB/MG Core to make available to biomedical investigators a wide range of methodologies and reagents relevant to understanding the molecular physiology of obesity and energy metabolism in animals and humans. This core applies molecular genetic and molecular biological techniques to the mapping, cloning and functional characterization of genes related to obesity and its comorbidities (diabetes and atherosclerosis). The services of this core are available to investigators new to obesity research, as well as to investigators working on obesity related projects that can be enriched and extended by the use of the facilities of this core.